INDEX. 353 



Microscope, new horizontal, 326. 

 Microscopes, achromatic, 2. 

 Miracia, gen., 46. 



efferata, D., 46. 



gTaci'Zis, D , 46. 

 Miracidse, fam., 46. 



Mitchell, William. Occultatioa of Aldebaran, July 16, 1849, 258. 

 Monstrilla, gen., Dana, 53. 

 viridis, D., 53. 

 Monstrillacea, 53. 

 Moon Culminations, 141. 

 Moon, Daguerreotype of, 196. 

 Mounds, at Marietta, old chart of, 220. 



N. 



Neptune, ephemeris of, 147. 



Neptune, satellite of, 136. 



Niagara Falls, retrogression of, 105. 



Nicothoidae, fam., 54. 



Nitrates, influence of, on the action by water on lead, 81. 



Nogagus, gen.. Leach, 58. 



validus, D., 58. 

 Northern Lakes, rise and fall of waters in, 131. 

 Nymphacea, 53, 61. 



O. 



(3ccuUations, 234. 

 Occultations of fixed stars, 185. 

 (Edicerus, gen., Kroyer, 217. 



Novi-Zealandice, D., 217. 

 Officers, 2, 159, 233, 266. 

 Ophiura acufera, Agassiz, 269. 

 Optical illusion, 300. 

 Orchestia, gen.. Leach, 202. 



dispar, D., 204. 



nitida, D., 204. 



qnadrimanus^ D., 204. 

 VOL. II, 45 



